Preheat your oven to 350°F (175°C). In a mixing bowl, combine the graham cracker crumbs with melted butter. Press this mixture firmly into the bottom of a 9-inch springform pan and bake for about 10 minutes until lightly golden.

In a large bowl, beat together the softened cream cheese and sugar until smooth. Add in the eggs one by one, mixing well after each addition. Then fold in the sour cream and vanilla extract until the mixture is creamy and well combined.

In another bowl, toss the sliced apples with cinnamon and brown sugar. Spread the apple mixture evenly over the crust.

Pour the cream cheese filling over the apple layer, smoothing it out with a spatula.

In a separate bowl, mix the oats with a little bit more brown sugar. Sprinkle this over the cheesecake filling.

Place the cheesecake in the preheated oven and bake for about 45-50 minutes, or until the center is set but still has a slight jiggle.

Let the cheesecake cool completely at room temperature, then refrigerate for at least 4 hours or overnight before serving for the best taste and texture.